You would have thought she could find a bikini to fit... designer Stella McCartney's costume takes the strain

The usually well-covered designer, who made her name clothing the rich and famous, showed little of her usual reserve as she stripped off to enjoy the sun while on a family holiday.

But for a designer who made her name as the purveyor of high quality clothing, it seems she failed to get a bikini to adequately contain her.

Tight fit: Designer Stella McCartney's bikini offers little coverage and her bust is threatening to spill out as she holidays in Mallorca

Stella's teeny triangle bikini strained to contain her chest, and the black bikini bottoms appeared to be distinctly Brazilian in style as they bared plenty of bottom flesh.

And later Stella appeared to be struggling to maintain her dignity after she waded into the water, as her less than ample chest spilled out of the bikini top.

Despite the lack of coverage, the designer who is married to magazine publisher Alasdhair Willis, certainly looked stunning in her bikini, despite giving birth to her third child in January this year.

The couple have three children together, Miller, three, Bailey, 20 months and Beckett, eight months.

Swim queen: The usually reserved Stella wades into the waters in her Brazilian-style bikini which showed off plenty of bottom flesh

Stella and her family are holidaying in Majorca, and have been seen enjoying the sights, and a day out at the local aquarium.

The ardent supporter of animal rights recently showed the courage of her convictions, after threatening legal action when a leading fashion house featured a model wearing lingerie from her collection beneath a mink fur coat.

Stella - who refuses to use fur or leather in her own designs – is said to have hit the roof and threatened legal action after spotting one of her bras in the advert for Hockley, a fur boutique based in Mayfair.

Malfunction: The bikini finally failed to hold the fashion designer as she spilled out of the leopard print number on the beach

The offending ad appears in the latest issue of Vogue and shows a model in a black lace McCartney bra draped in a £6,450 full-length mink black and white ‘Atlas’ coat accessorised with a leather belt.

‘Stella went absolutely ballistic when she saw it,’ a source at her store in Mayfair told The Mail on Sunday.

‘I have never seen her so angry. She hit the roof and said that she planned to sue.'

Stella is holidaying in Majorca with husband Alasdhair Willis, daughter Bailey, and sons Miller and Beckett